She hunts. She fishes. She was voted Miss Congeniality after winning a beauty pageant in her small town in Alaska. She is a mother of five and a churchgoer who says her favourite meal is moose stew.

But the quality that may serve Sarah Palin best after being chosen by John McCain as his running mate yesterday may be the competitiveness and determination to win that earned her the name Sarah Barracuda for her sharp elbows as high school basketball player.

Palin, 44, the first female governor of Alaska and the first woman on a Republican presidential ticket, has a life story that could make a conservative Republican swoon. But until yesterday even Palin thought it far-fetched that she could be a figure on a national stage.

In an interview last month, she even let slip that she did not think the job of vice-president was very meaningful. "As for that VP talk all the time, I'll tell you, I still can't answer that question until somebody answers for me what is it exactly that the VP does every day," she told CNBC. "I'm used to being very productive and working real hard in an administration."

McCain is hoping his selection will help win over disaffected supporters of Hillary Clinton who might rally towards a woman candidate, and that Palin's reputation as an anti-corruption crusader could banish the aura of the past that hangs over his candidacy.

Born in Idaho, Palin moved to Alaska as a child. She married her high school sweetheart, Todd Palin, who works on the oilfields and is a champion snowmobile racer. The couple live on a lake, own a float plane, and have raised five children. Their eldest son is in the army and is about to deploy to Iraq. Their youngest son is six months old and was born with Down's syndrome.

She is a fierce opponent of abortion and same-sex marriage. She supports the death penalty and the teaching of creationism in schools. Palin is an enthusiast for the outdoors and a gun owner, and is opposed to environmental restrictions on drilling in Alaska.

While virtually unknown to the average American before yesterday, Palin has been a rising star in political circles since 2006. She challenged the incumbent Republican governor, who was then under the shadow of a corruption scandal, in the state primary, and went on to beat her Democratic opponent - a rare bright light for Republicans in 2006 who were losing across the map.

As governor, she has demonstrated a populist flair. She sold the official governor's plane and took commercial flights. She drives to work in the family Volkswagen Jetta. In an attempt to soften the burden on Alaskans of high petrol prices, she proposed giving every household a $100 (£55) energy debit card. Palin has also tried to cut government spending, shutting down a bridge project that would have cost $400m.

But she has a long list of political enemies. She is also under investigation into whether she intervened to sack a state trooper who was involved in a divorce and custody battle with her sister. Palin is alleged to have transferred the commissioner of public safety, Walter Monegan, to a job at the state alcohol board last month, after he refused to sack the police official.